U.S. patent application number 16/114530 was filed with the patent office on 2019-03-07 for electric power tool.
This patent application is currently assigned to MAKITA CORPORATION. The applicant listed for this patent is MAKITA CORPORATION. Invention is credited to Junya ISHIKAWA.
Application Number | 20190070705 16/114530 |
Document ID | / |
Family ID | 65363677 |
Filed Date | 2019-03-07 |
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United States Patent
Application |
20190070705 |
Kind Code |
A1 |
ISHIKAWA; Junya |
March 7, 2019 |
ELECTRIC POWER TOOL
Abstract
In an angle electric power tool 1 in which an output axis P
intersects and is orthogonal to a motor axis J, a battery
attachment portion 40 is provided to the rear of a grip 30 so as to
extend in the rearward direction and a battery pack 50 is
configured to be attached to an upper surface of said battery
attachment portion 40. Because of this configuration, the battery
pack 50 does not directly come into contact with a working surface
W, thereby preventing flaws and scratches on the working surface
W.
Inventors: |
ISHIKAWA; Junya; (Anjo-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MAKITA CORPORATION |
Anjo-shi |
|
JP |
|
|
Assignee: |
MAKITA CORPORATION
Anjo-shi
JP
|
Family ID: |
65363677 |
Appl. No.: |
16/114530 |
Filed: |
August 28, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B24B 23/03 20130101;
B24B 27/0076 20130101; B24D 9/08 20130101; B24D 13/147 20130101;
Y02E 60/10 20130101; B25F 5/02 20130101; B25F 5/008 20130101; B60S
3/06 20130101; B24B 41/007 20130101; H01M 2/1022 20130101; B24B
23/028 20130101; B24D 13/14 20130101; H01M 2220/20 20130101 |
International
Class: |
B24B 23/02 20060101
B24B023/02; B24B 27/00 20060101 B24B027/00; B24D 13/14 20060101
B24D013/14; B24D 9/08 20060101 B24D009/08; B25F 5/02 20060101
B25F005/02; B60S 3/06 20060101 B60S003/06; H01M 2/10 20060101
H01M002/10 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 5, 2017 |
JP |
2017-170254 |
Claims
1. An electric power tool, comprising: a tool main body that houses
an electric motor in a main body housing; an output shaft that
protrudes from a lower portion of the tool main body and extends in
an up-to-down direction; and a battery attachment portion for
attaching a slide-attachment type battery pack that supplies power
to the electric motor, the battery attachment portion being
disposed at the rear portion of the tool main body, wherein, the
battery pack is attached to an upper surface of the battery
attachment portion.
2. The electric power tool according to claim 1, wherein the
battery pack is attached to the upper surface of the battery
attachment portion such that its shortest dimension is aligned with
the up-to-down direction.
3. The electric power tool according to claim 1, wherein an upper
end of the battery attachment portion region protrudes upward
higher than the upper surface of the battery pack that is attached
to the battery attachment portion.
4. The electric power tool according to claim 1, wherein an elastic
member is disposed on the lower surface of the battery attachment
portion.
5. An electric power tool, comprising: a tool main body that houses
an electric motor in a main body housing; an output shaft that
protrudes from a lower portion of the tool main body and extends in
an up-to-down direction; and a battery attachment portion for
attaching a slide-attachment type battery pack that supplies power
to the electric motor, the battery attachment portion being
disposed at the rear portion of the tool main body, wherein, an
elastic member is disposed on a lower surface of the battery
attachment portion.
6. A polisher, comprising: a tool main body that houses an electric
motor in a main body housing; an output shaft that protrudes from a
lower portion of the tool main body and extends in an up-to-down
direction; and an elastic member that is disposed on at least a
part of the lower portion of the tool main body.
7. The electric power tool according to claim 3, wherein an elastic
member is disposed on the upper end of the battery attachment
portion region.
8. The electric power tool according to claim 1, further comprising
a leg used for placing the electric power tool upside down that is
formed at the top of the main body housing, the leg being made of
an elastic member.
9. The electric power tool according to claim 5, wherein the motor
housed in the tool main body is a brushless motor that includes a
cylindrically shaped stator that is fixed to the main body housing
as well as a rotor that is rotatably supported on the inner
circumferential periphery of the stator via a motor shaft, the
motor shaft being orthogonal to the output shaft.
10. The electric power tool according to claim 9, wherein the motor
shaft is rotatably supported by a front bearing and rear bearing at
a region at the front of said shaft, and at the rear of said shaft,
respectively, wherein the longitudinal axis of the motor shaft is
parallel to the longitudinal axis of the tool main body, where the
tool main body is formed in a roughly tubular shape.
11. The electric power tool according to claim 10, wherein a
cooling fan is inserted at the front region of the motor shaft, but
to the rear of the front bearing, the cooling fan fully surrounding
the motor shaft and fitting with the shaft in a tight manner due to
the presence of the front bearing.
12. The electric power tool according to claim 10, wherein a drive
side bevel gear is provided at the front most region of the motor
shaft, immediately in front of and adjacent to the front bearing,
wherein the drive said bevel gear is fully surrounds and is tightly
fitted on the motor shaft.
13. The electric power tool according to claim 12, wherein, a
driven side bevel gear may be provided on the output shaft, such
that it fully surrounds and is tightly fitted on the upper region
of the output shaft, but not at the uppermost end.
14. The electric power tool according to claim 13, wherein the
driven side bevel gear is present to the front of and lower than
the drive side bevel gear, wherein the two gears are
perpendicularly adjacent to each other such that their gears may
enmesh, to enable a driving action from the motor shaft to the
output shaft, wherein the output shaft may rotate by means of the
bevel gear complementarily engaging with the bevel gear.
15. The electric power tool according to claim 14, wherein the
output shaft may rotate about its longitudinal axis due to the
driving action of the motor shaft.
16. The electric power tool according to claim 14, wherein an
eccentric shaft may be integrally formed with the output shaft,
extending downward from the lower surface of the output shaft, such
that the longitudinal axis of the eccentric shaft may be disposed
parallel to and spaced apart from the output axis by a
predetermined distance in the radial direction.
17. The electric power tool according to claim 16, wherein a lower
portion of the tool main body surrounding the eccentric shaft
includes a cylindrical-shaped moving main body, which includes
engagement teeth on its outer peripheral circumference, as well as
a cylindrically shaped dependent body, wherein the moving main body
may rotate within the dependent body.
18. The electric power tool according to claim 17, wherein the
diameter of the dependent body is larger than the moving main body
but where the moving main body may protrude lower than the
dependent body, such that the lower end of the moving main body
forms a tip end at the lowest point of the output shaft.
19. The electric power tool according to claim 17, wherein the
dependent body may be selectively locked or unlocked, such that the
moving main body may rotate around the longitudinal axis of the
output shaft, or around the longitudinal axis of the output shaft
as well as about the eccentric shaft, resulting in a changing
position of the moving main body with respect to the dependent
body.
20. The electric power tool according to claim 18, wherein a
circular base portion, which may include a polishing pad which can
be attached to the tip end formed by the moving main body at the
lower end of the output shaft.
Description
CROSS-REFERENCE
[0001] This application claims priority to Japanese patent
application serial number 2017-170254, filed on Sep. 5, 2017, the
contents of which are incorporated herein by reference in their
entirety.
TECHNICAL FIELD
[0002] The present invention generally relates to an electric power
tool such as, for example, a polisher that is used for polishing
work on a coating surface of an automobile body.
BACKGROUND ART
[0003] Generally, in an angle polisher used for performing
polishing work, or in an angle disc grinder used for performing
grinding work, an output shaft to which an end tip tool such as a
polishing pad or a circular whetstone is attached is disposed
perpendicular to a motor shaft of an electric motor serving as a
power source. Angle electric power tools are disclosed in
non-patent literature such as, for example, Makita General
Catalogue No. Z11203C1 published June, 2017, which shows a model
No. 9237C on page 97. When disc grinders such as those previously
known are used, some flaws or scratches which result on the working
surface from application of the polisher do not raise any problem
since a working surface (grinding object) is, for example, stone
material. However, when the polisher is used on another working
surface, such as e.g. an automobile body, even a slight flaw or
scratch may cause a problem since the working surface is more
sensitive. Because of this reason, for example, special care needs
to be taken when operating such a polisher on such a working
surface. In particular, in polishing the working surface when the
polisher used is operated by, for example, AC power, an operator
must be careful not to contact the power cable with the working
surface. Also, when the polisher used is operated by DC power, the
operator must be careful not to contact a battery pack to the
working surface.
[0004] The angle polisher Model No. 9237C disclosed in the
above-described non-patent document is operated by AC power.
[0005] When said polisher is used, the user may need to stretch
their hand with respect to a wide working surface (polishing
surface) such as an automobile body, for using the polisher on said
surface. In this case, if the user uses the polisher to which a
battery pack is attached, in an up-to-down vertical direction, and
in addition the user is positioned upwards relative to the polisher
(in a direction away from the polishing surface), then in this case
when the user attempts to use the polisher on the working surface,
the battery pack may interfere with the user's hand, which may
prevent the user from sufficiently stretching their hand, and may
force the user to perform a polishing work with a limited range of
movement, resulting in a limited tight posture. In this respect,
this situation presents a problem of maneuverability, impairing the
ease of use of the polisher.
[0006] Furthermore, a lower portion of the polisher may scratch,
for example, an automobile body etc.
[0007] Thus, as a result of the mentioned deficiencies in the art,
there is a need for polishers used in the aforementioned polishing
work, on, for example, automobile body surfaces, to successfully
prevent or suppress flaws or scratches from developing on the
working surface as a result of application of said polisher. In
addition, there is also a need for the user being able to use the
polisher in a comfortable posture while stretching their hand,
thereby improving maneuverability and enhancing ease of use of the
polisher.
SUMMARY
[0008] In one exemplary embodiment of the present disclosure, an
electric power tool includes a tool main body that houses an
electric motor in a main body housing, an output shaft that
protrudes from a lower portion of the tool main body and extends in
an up-to-down direction, and a battery attachment portion for
slide-attaching a slide-attachment type battery pack that supplies
power to the electric motor. The battery attachment portion is
disposed at the rear portion of the tool main body. The battery
pack is attached to an upper surface of the battery attachment
portion.
[0009] According to this embodiment, in particular, the battery
pack is attached to the upper surface side of the battery
attachment portion, which is provided at the rear portion of the
tool main body. Because of this configuration, when the user is
operating the device in a working posture, where a tip end tool is
brought into contact with a working surface, the working surface is
situated below the lower portion of the battery attachment portion,
wherein the battery pack is attached to the upper surface side of
the battery attachment portion, thus preventing the battery pack
from interfering with the working surface.
[0010] In another exemplary embodiment of the disclosure, the
battery pack is attached to the upper surface of the battery
attachment portion such that its shortest dimension is aligned in
the up-to-down vertical direction.
[0011] According to this embodiment, in particular, the battery
pack is attached to the upper surface of the battery attachment
portion such that its thickness direction (dimension of the
shortest side) is aligned in the up-to-down direction, and thus the
battery pack is attached in a compact manner to said portion such
that its protruding length in the up-to-down direction is the
shortest of all of its dimensions. Because of this configuration,
the user need not worry about their hand interfering with the
battery pack, and consequently the user's range of movement is
expanded, and they can carry out a work in a comfortable posture
(such that the battery pack does not become an obstruction for the
user). In this respect, such a configuration of the battery
attachment portion and the battery pack enhances maneuverability
and ease of use of the electric power tool.
[0012] Furthermore, for example, when a slide-type battery pack
whose thickness is large in the up-to-down direction according to a
larger-than-normal battery capacity is used, as a result of the
battery pack being attached to the upper surface side of the
battery attachment portion, a lower end of the battery pack does
not easily approach the working surface to be polished.
[0013] In another exemplary embodiment of the disclosure, an upper
end of the battery attachment portion region protrudes upward
higher than the upper surface of the battery pack that is attached
to the battery attachment portion.
[0014] According to this embodiment, when the electric power tool
is placed in an inverted manner upside down, flaws or scratches
made by the battery pack on the working surface to be polished may
be prevented.
[0015] In another exemplary embodiment of the disclosure, an
elastic member is disposed on a lower surface of the battery
attachment portion.
[0016] According to this embodiment, flaws or scratches on the
working surface to be polished can be prevented when the battery
attachment portion incidentally happens to contact said working
surface.
[0017] In another exemplary embodiment of the present disclosure,
an electric power tool includes a tool main body that houses an
electric motor in a main body housing, an output shaft that
protrudes from a lower portion of the tool main body and extends in
an up-to-down direction, and a battery attachment portion for
slide-attaching a slide-attachment type battery pack that supplies
power to the electric motor. The battery attachment portion is
disposed at the rear portion of the tool main body. Furthermore, an
elastic member is disposed on a lower surface of the battery
attachment portion.
[0018] According to this embodiment, flaws or scratches can be
prevented by the elastic member when the battery attachment portion
directly interferes with the working surface.
[0019] In another exemplary embodiment of the present disclosure, a
polisher includes a tool main body that houses an electric motor in
a main body housing, an output shaft that protrudes from a lower
portion of the tool main body and extends in an up-to-down
direction, and an elastic member that is disposed on at least a
part of the lower portion of the tool main body.
[0020] According to this embodiment, flaws or scratches can be
prevented by the elastic member when the main body housing directly
interferes with the working surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is an overall perspective view of an electric power
tool according to an exemplary embodiment of the present
disclosure.
[0022] FIG. 2 is an overall side view of the electric power tool
according to the exemplary embodiment.
[0023] FIG. 3 is a top view of the electric power tool according to
the exemplary embodiment viewed in the direction indicated by an
arrow (III) in FIG. 2.
[0024] FIG. 4 is a bottom view of the electric power tool according
to the exemplary embodiment viewed in the direction indicated by an
arrow (IV) in FIG. 2.
[0025] FIG. 5 is a left-side view of a battery attachment portion
in a state where a battery pack is detached therefrom in a rearward
direction.
[0026] FIG. 6 is a top view of the battery attachment portion in
the state where the battery pack is detached therefrom in the
rearward direction, viewed in the direction indicated by an arrow
(VI) in FIG. 5.
[0027] FIG. 7 is a bottom view of the battery attachment portion in
the state where the battery pack is detached therefrom in the
rearward direction, viewed in the direction indicated by an arrow
(VII) in FIG. 5.
[0028] FIG. 8 is a longitudinal sectional view of the electric
power tool according to the exemplary embodiment.
[0029] FIG. 9 is the cross-sectional view of the electric power
tool according to the exemplary embodiment taken along line
(IX)-(IX) of FIG. 2, showing a longitudinal sectional view of a
left and right inlet port.
[0030] FIG. 10 is a left-side view of the electric power tool from
the rear portion of the tool main body to the front portion of a
grip thereof, showing a state where an auxiliary filter is attached
to the inlet port with a frame body.
[0031] FIG. 11 is a left-side view of the electric power tool from
the rear portion of the tool main body to the front portion of the
grip, showing a state where the auxiliary filter and the frame body
are detached from the inlet port.
[0032] FIG. 12 is a perspective view of a single frame body with
the filter detached from the inlet port, viewed from the
outside.
[0033] FIG. 13 is a perspective view of the single frame body with
the filter detached from the inlet port, viewed from the
inside.
[0034] FIG. 14 is a cross-sectional view of the electric power tool
taken along the same line as the line (IX)-(IX) of FIG. 2, showing
the state where an auxiliary filter is attached to the inlet port
by use of a frame body according to a second embodiment having a
different attaching structure.
[0035] FIG. 15 is a left-side view of the electric power tool
according to the second embodiment from the rear portion of the
tool main body to the front portion of the grip, showing the state
where the auxiliary filter is attached to the inlet port by use of
the frame body having the different attaching structure of the
second embodiment.
[0036] FIG. 16 is a left-side view of the electric power tool
according to the second embodiment from the rear portion of the
tool main body to the front portion of the grip, showing the state
where the auxiliary filter and the frame body having the different
attaching structure of the second embodiment are detached from the
inlet port.
[0037] FIG. 17 is a perspective view of the frame body and the
filter of the second embodiment that is detached from the inlet
port, viewed from the outside.
[0038] FIG. 18 is a perspective view of the frame body and the
filter of the second embodiment that is detached from the inlet
port, viewed from the inside.
DETAILED DESCRIPTION
[0039] The detailed description set forth below, when considered
with the appended drawings, is intended to be a description of
exemplary embodiments of the present invention and is not intended
to be restrictive and/or to represent the only embodiments in which
the present invention can be practiced. The term "exemplary" used
throughout this description means "serving as an example, instance,
or illustration," and should not necessarily be construed as
preferred or advantageous over other exemplary embodiments. The
detailed description includes specific details for the purpose of
providing a thorough understanding of the exemplary embodiments of
the invention. It will be apparent to those skilled in the art that
the exemplary embodiments of the invention may be practiced without
these specific details. In some instances, these specific details
refer to well-known structures, components and/or devices that are
shown in block diagram form in order to avoid obscuring significant
aspects of the exemplary embodiments presented herein.
[0040] Representative, non-limiting embodiments according to the
present disclosure will be described with reference to FIGS. 1 to
18. As shown in FIGS. 1 to 4, a rechargeable polisher 1 is
exemplified as an electric power tool 1 in this embodiment. FIG. 8
shows the internal cross-sectional structure (perpendicular to the
left-right axis) of the electric power tool 1. The electric power
tool 1 may include a tool main body 10 that houses the electric
motor 11 as a drive source, an output portion 20 that is provided
at a front portion of the tool main body 10, a grip 30 that is
provided at a rear portion of the tool main body 10, and a battery
attachment portion 40 that is provided at a rear portion of the
grip 30, to the rear of the grip 30. In the following embodiments,
the upward, rearward, leftward and rightward directions are
described relative to the position of a user who holds the grip 30
with his or her body facing the front portion of the tool main body
10. A tip end tool 2 such as, for example, a polishing pad may be
attached to a lower surface side of the output portion 20. With
regard to the orientation of directions recited as up and down, the
side of the tip end tool 2 is referred to as the downward
direction, where the rest of the output portion 20, is upward
relative to the tip end tool 2, as shown in FIG. 8.
[0041] As shown in FIGS. 1 to 4 and FIG. 8, the tool main body 10
may have a roughly tubular shape extending in the front-to-rear
direction, which corresponds to the longitudinal axis thereof (the
tool main body length direction). As shown in FIG. 8, the electric
motor 11 that is housed in the tool main body 10 may be a brushless
motor which includes a cylindrical-shaped stator 11a that is fixed
to the main body housing 12 of the tool main body 10 as well as a
rotor 11b that is rotatably supported on the inner circumferential
periphery of the stator 11a via a motor shaft 11c. The motor shaft
11c may be rotatably supported via a front bearing 14 and a rear
bearing 15. The longitudinal axis of the motor shaft 11c (motor
axis J), parallel to the longitudinal axis of the tool main body
10, may correspond to the front-to-rear lengthwise direction
(corresponding to the tool main body length direction) of said
shaft 11c. A cooling fan 17 may be supported by the motor shaft
11c, by being inserted on and rotating about the longitudinal axis
of said shaft 11c, between the front bearing 14 and the rotor 11b.
As a result of the cooling fan 17 being inserted on said shaft 11c,
where it fully surrounds said shaft 11c, and fits with said shaft
11c in a tight manner due to the presence of front bearing 14, the
cooling fan 17 may rotate synchronously with the motor shaft
11c.
[0042] A controller 13, which houses a control circuit board by use
of which operation of the electric motor 11 is controlled, may be
disposed below the electric motor 11. The controller 13 may have a
rectangular flat-plate shape and may be attached to the inner
peripheral surface of the lower basal portion of the main body
housing 12. The controller 13 may be housed in the main body
housing 12 such that it is laid flat in a state where that the
shortest dimension (thickness) of said controller 13 is aligned in
the up-to-down direction, and its top and bottom rectangular base
may extend in the front-rear left-right directional plane,
perpendicular to the vertical up-to-down direction. As seen in FIG.
1, spaced apart exhaust window vents 19 in a grille-shaped manner
may be provided around the cooling fan 17 on the left and right
side upper portions of the front end of the tool main body 10.
Outside air may be introduced from an intake grille 60 that is
disposed on the rear side of the tool main body 10 by use of the
cooling fan 17 which operates by rotation of electric motor 11,
sucking in air through the intake grille 60. The introduced outside
air (cooling air) may then cool the electric motor 11 and the
controller 13. After cooling said components, in a terminal point
of the intake air flow path through tool main body 10, the cooling
air may then be discharged from the grille comprising exhaust
window vents 19 to the outside by air flow generated by the same
previous rotation of the cooling fan 17.
[0043] A drive-side bevel gear 16 may be provided on the front
portion of the motor shaft 11c. The bevel gear 16 may engage with a
driven-side bevel gear 25 on the side of the output portion 20,
which is frontwards and orthogonal relative to the bevel gear 16.
The driven-side bevel gear 25 may be rotatably supported by an
interior of a metal-made gear housing 21 that is connected and
adjacent to the front portion of the main body housing 12 of the
tool main body 10.
[0044] An output shaft 24 is formed within the interior of the gear
housing 21, and is rotatably supported by the gear housing 21 via
an upper bearing 22 and a lower bearing 23, which are present as
part of the gear housing 21. The driven-side bevel gear 25 may be
connected to the output shaft 24, wherein the driven-side bevel
gear 25 fully surrounds and is fitted on the output shaft 24. The
output shaft 24 may rotate by means of the drive-side bevel gear 16
complementarily engaging with the driven-side bevel gear 25, where
the two gears are enmeshed with each other. The output shaft 24 may
rotate about its longitudinal axis in the vertical up-to-down
direction (around an output axis P). As shown in FIG. 8, the output
axis P may be orthogonal to and intersect the motor axis J, which
shows that the electric power tool 1 is an angle polisher.
[0045] An eccentric shaft 26 may be integrally formed with the
output shaft 24, extending downward from the lower surface of said
output shaft 24. The longitudinal axis of the eccentric shaft 26
may be disposed parallel to and spaced apart from the output axis P
by a predetermined distance. A cylindrical-shaped moving main body
27, which includes engagement teeth on its outer peripheral
circumference, may be supported to fit completely around the
eccentric shaft 26 in a rotatable manner via two bearings 27a,
which surround the axis of the eccentric shaft 26 in a tight
fitting configuration. Furthermore, a cylindrical-shaped dependent
body 28, which has a larger diameter than the moving main body 27,
may be supported to fit completely around the moving main body 27
by the gear housing 21 in a rotatable manner about the output axis
P. The moving main body 27 may protrude downwards from the gear
housing 21. A circular base portion 29 for attaching, for example,
a pad as the tip end tool 2 may be attached to a portion 27b formed
integrally with the moving main body 27 that protrudes below the
moving main body 27.
[0046] The moving main body 27 moves synchronously with the
eccentric shaft 26 in an eccentric manner by the rotation of
eccentric shaft 26 around the output shaft 24, when the output
shaft 24 itself is driven and rotates about its own longitudinal
axis. In a state where the dependent body 28 engaged with the
moving main body 27 is rotatable, the moving main body 27 may only
revolve around the output axis P; i.e., because due to the
dependent body 28 being circular and also rotating about axis P at
its radial center, the engagement position of the moving main body
27 with respect to the dependent body 28 is not changed. However,
in a state where rotation of the dependent body 28 around the axis
P is locked, an engagement position of the moving main body 27 with
respect to the dependent body 28 may change with the rotation of
moving main body 27 around the output axis P, and thus the moving
main body 27 may not only rotate around the output axis P but also
rotate eccentrically with rotation about the eccentric shaft 26
resulting in a shift of position relative to the dependent body 28.
In a soft mode in which the tip end tool 2 only rotates around the
output axis P, a polishing work with a clean finish may be
performed. In contrast, in a powerful mode in which the tip tool
end 2 not only rotates around the output axis P but also rotates
eccentrically about the eccentric shaft 26, shifting position
relative to the dependent body 28, a rapid polishing work may be
performed. A mode select dial 3 that is disposed on the left side
of the output portion 20 enables the user to select between the
soft mode (a state where the dependent body 28 is rotatable) and
the powerful mode (a state where rotation of the dependent body 28
is locked).
[0047] The outer peripheral surface of the gear housing 21 may be
covered by a resin-made auxiliary housing 21a. A sub grip 21b for
the user to hold the rechargeable polisher 1 with one hand may
protrude forward from the front side of auxiliary housing 21a,
forming the front most portion of the polisher. A frontal lower
surface of the sub grip 21b, as well as an upper surface of the
auxiliary housing 21a may be covered by elastic resin layers 21c
and 21d, respectively, made of elastomer rubber, for the purpose of
preventing flaws or scratches on the working surface W. Two legs
21e used for placing the tool upside down may be formed at the top
of the elastic resin layer 21d that covers the upper surface of the
auxiliary housing 21a. When the electric power tool 1 is placed
upside down, the elastic resin-made legs 21e may contact the
surface on which the polisher 1 is placed, thereby preventing flaws
or scratches on the working surface W.
[0048] A grip 30 with which the user may hold the polisher 1 is
provided on a rear portion of the tool main body 10, extending in
the rearward direction. The grip 30 may be formed in a tubular
shape with a diameter sized small enough so that the user can
easily hold the polisher 1 with one hand. As shown in FIGS. 2 and
4, a switch lever 31 which the user may pull upward by using their
fingertip while simultaneously maintain a hold on the grip 30 may
be provided on the front lower surface of the grip 30. A start lock
lever 33 may be provided on the front side of the switch lever 31.
When the start lock lever 33 is moved rightwards or leftwards, a
locked state of the switch lever 31 may be released, putting the
electric power tool 1 in an on-operable state.
[0049] As shown in FIG. 8, a switch main body 32 may be housed in
the front portion of the interior of the grip 30, located above the
switch lever 31. When the switch lever 31 is pulled upwards by the
user, the switch main body 32 may be turned on. When the switch
main body 32 is turned on, the electric motor 11 may start and the
tip end tool 2 may rotate. A rotation number of the electric motor
11 can be adjusted according to the extent the switch lever 31 is
pulled upwards. A disk-shaped lock-on button 34 may be provided on
the left side of the grip 30 above the switch lever 31. When the
lock-on button 34 is pressed while the switch lever 31 is being
pulled upwards, the switch lever 31 may be held (locked) at the
highest position to which it is pulled up. By locking the switch
lever 31 at the highest pulled position, the user can easily
perform a polishing work for a long time without having to
constantly hold the switch lever 31 with their finger at the
highest pulled position. When the switch lever 31 is pulled again,
from said locked position, the locked state of the switch lever 31
induced by the pressing of lock-on button 34 may be released and
the switch lever 31 can be returned downwards to an
off-position.
[0050] As shown in FIGS. 1 to 3, a speed adjustment dial 35 may be
provided on the upper front surface of the grip 30. By positioning
the speed adjustment dial 35 at this position, the user can rotate
the speed adjustment dial 35 with a finger while maintaining a hold
with their hand on the grip 30. By rotating the speed adjustment
dial 35 with a finger in this manner, the rotation number of the
electric motor 11, governing speed, can be adjusted.
[0051] A battery attachment portion 40 may be provided on a rear
portion of the grip 30 (facing the user). A battery pack 50,
forming the rearmost part of the rechargeable polisher 1, may be
attached to the battery attachment portion 40 as a power source.
The battery attachment portion 40 may be formed in a flat plate
shape (a pedestal shape) extending rearwards from a rear end of the
grip 30. A vertical wall 36 extending mainly in the up-to-down
direction may be integrally formed with the grip 30 at the rear end
portion of the grip 30. In particular, the vertical wall 36 may be
formed in a curved, concave shape in the forward direction as shown
in FIG. 1. A top portion of the vertical wall 36 may be covered
with an elastic resin layer 36a made of elastomer rubber. As shown
in FIGS. 2 and 5, the battery attachment portion 40 may be provided
such that it extends rearwards from a lower portion of the vertical
wall 36.
[0052] One battery pack 50 can be mechanically and electrically
attached to an upper surface of the battery attachment portion 40.
As shown in FIG. 6, a pair of rails 41 may be provided on the upper
surface of the battery attachment portion 40, joining together at
the front of the upper surface of the battery attachment portion 40
in a concave manner with respect to the front direction. The slide
attachment direction for attaching the battery pack 50 to the
battery attachment portion 40 may be in the front-to-rear direction
in accordance with the rear portion of the pair of rails 41. As
shown in FIGS. 5 to 7, the battery pack 50 can be attached to the
upper surface side of the battery attachment portion 40 by sliding
the battery pack 50 from the rear to the front of battery
attachment portion 40. Conversely, the attached battery pack 50 can
be detached from the upper surface of the battery attachment
portion 40 by sliding the battery pack 50 in the rearward
direction. A positive terminal 42 and a negative terminal 43 may be
disposed between the pair of the rails 41. A lock groove 44 on the
battery attachment portion 40 may be provided for engaging with a
lock claw 56 on the battery pack 50.
[0053] A lower portion of the battery attachment portion 40 may be
covered with an elastic resin layer 45 made of elastomer resin. In
particular, in the present embodiment, the entire outer peripheral
circumference of the ovular lower surface of the battery attachment
portion 40 may be covered with the elastic resin layer 45 as shown
in FIG. 7. This way, even if the battery attachment portion 40
contacts the working surface W, flaws or scratches are prevented
from being formed on the working surface W by the elastic resin
layer 45.
[0054] The battery pack 50 may include a plurality of lithium ion
battery cells that are housed in a battery case formed
approximately in a rectangular parallelepiped shape. The battery
pack 50 may be used as a power source which is inter-compatible
with other chargeable electric power tools such as, for example, a
screw driver etc. The battery pack 50 can be recharged by use of a
dedicated charger and repeatedly used as a power source of said
electric power tools. The battery pack 50 may be attached to the
battery attachment portion 40 such that the longitudinal direction
of the battery pack 50 is aligned with the front-to-rear direction,
its transverse direction is aligned with the left-to-right
direction, and its thickness direction (the shortest dimension) is
aligned with the vertical up-to-down direction.
[0055] As shown in FIG. 7, a pair of rail receiving portions 52 for
guiding the pair of rails 41 of the battery attachment portion 40
to engage with the battery pack 50 in a complementary fitting
manner may be provided on a connection portion 51 of the battery
pack 50. The battery pack 50 may be guided in a sliding direction
(in the front-to-rear direction) by engaging the rails 41 with the
rail receiving portions 52, resulting in an interlocking
connection. Similarly, a positive terminal receiving portion 53 for
advancing (receiving) the positive terminal 42 and a negative
terminal receiving portion 54 for advancing (receiving) the
negative terminal 43 may be provided between the pair of the rail
receiving portions 52. When the positive terminal 42 advances to
the positive terminal receiving portion 53 and the negative
terminal 43 advances to the negative terminal receiving portion 54,
respectively, by the slide attaching action of the battery pack 50
to the battery attachment portion 40 by being moved in the forward
direction, both terminals 42 and 43 may be electrically connected
to the battery pack 50. A connector 55 comprising a signal
connector terminal may be provided between the positive terminal
receiving portion 53 and the negative terminal receiving portion
54. This connector 55 may be used for transmitting/receiving
control signals between the battery pack 50 and the charger while
the battery pack 50 is being charged by the charger, but is not
used (connected) when the battery pack 50 is attached to the
battery attachment portion 40.
[0056] As shown in FIGS. 5 and 7, the lock claw 56 may be provided
at the rear portion of the connection portion 51 of the battery
pack 50, forming the bottom most portion of the battery pack 50.
The lock claw 56 may be biased to protrude in the downward
direction, but may be pushable upwards against said bias. The
battery pack 50 may be locked in an attached manner to the battery
attachment portion 40 by an engagement of the lock claw 56 with the
lock groove 44. A lock release button 57 for moving the lock claw
56 to an unlock position (i.e. upward) may be provided on a rear
side of the battery pack 50. When the lock release button 57 is
pushed in the upward direction, the lock claw 56 may be moved
upwards against the biasing force. When the lock claw 56 is moved
upwards, it is extracted from the lock groove 44, and the battery
pack 50 can be slid rearwards in the detaching direction.
[0057] As discussed above, the upper portion of the vertical wall
36 may be covered with the elastic resin layer 36a made of
elastomer rubber. As shown in FIG. 8, in a state where the battery
pack 50 is attached to the upper surface of the battery attachment
portion 40, positions of elastic resin layer 36a and the battery
attachment portion 40 in the up-to-down direction may be configured
in an appropriate manner, such that the elastic resin layer 36a is
higher in the up-to-down direction compared to the entirety of the
upper surface of battery pack 50. Similar to the above-mentioned
reverse legs 21e, the elastic resin layer 36a may also serve as a
outwardly protruding portion which may be placed on and contact the
working surface W when the electric power tool 1 is placed
reversely upside down to be placed on the working surface W, where
the resin contacts the working surface W instead of the upper
surface of battery pack 50, because as shown in FIG. 8 the resin
layer 36a is higher than the entirety of battery pack 50. Thus by
the elastic resin layer 36 contacting the working surface W, the
battery pack 50 may not directly come into contact with the working
surface W, thereby preventing occurrence of trouble such as, for
example, the formation of unintended flaws or scratches on the
working surface W.
[0058] Other than the above-mentioned places, some other portions
of the electric power tool 1 may also be covered with protruding
elastic resin layers in a similar manner in order to prevent flaws
or scratches on the working surface W. In the present embodiment,
the lower surface of the rear portion of the tool main body 10 may
be covered with the elastic resin layer 18 made of elastic rubber.
As shown in FIGS. 2 and 4, an angled corner portion may be formed
at the lower surface of the rear portion of the tool main body 10
such that, from front-to-rear, the lower peripheral surface of the
rear portion of the tool main body 10 is tilted upwards at a
positive angle of approximately 45 degrees relative to the
longitudinal front-to-rear horizontal axis of the tool main body
10, as the tool main body 10 extends rearwards. In the present
embodiment, an entirety of this portion may be covered with the
elastic resin layer 18. Due to its surface characteristics, this
elastic resin layer 18 can prevent the formation of flaws or
scratches on the working surface W, compared of the case where the
tool main body 10 is not covered by such an elastic resin
layer.
[0059] Intake window grille 60 for introducing outside air may be
provided on both right and left sides of the rear portion of the
tool main body 10. When the electric motor 11 starts and the
cooling fan 17 rotates, said rotation may generate a vacuum effect,
sucking outside air from the intake window grille 60 into the
interior of the tool main body 10 to cool the electric motor 11
etc. FIGS. 9 to 18 show the intake window grille 60 in detail. The
right and left intake window grille 60 may have the same structural
configuration, and oppositely mirror each other about the
longitudinal front-to-rear axis. The intake window grille 60 may
span the entirety of a vertically extended opening 61. The intake
window grille 60 may also comprise a plurality of vertically spaced
apart ventilation ribs 62 extending in the front-to-rear direction
may be provided spaced inward from the opening 61, where the
plurality of ventilation ribs 62 spans the vertical length of the
opening 61 of the intake window grille 60, thereby forming in a
drain board shape. A filter F may be inserted onto the intake
window grille 60, over the ventilation ribs 62 of intake window
grille 60. The filter F may include a plurality of squares. In more
detail, in this embodiment, one side of the square may be 1 mm-1.5
mm, or 0.1 mm-0.3 mm. The filter F may be formed in another
configuration such as, for example, a parallelogram or a rectangle,
and its length may be chosen arbitrarily to be a predetermined
amount. A filter frame 65 may be integrally formed around the
filter F. The filter F may be attached to the opening 61 along the
outer surface side of the ventilation ribs 62. The filter F can be
retained at a predetermined position by inserting it snugly forming
a tight fit with the inner peripheral surface about the entire
perimeter of the opening 61. Two retaining configurations of the
filter frame 65 with respect to the opening 61 will be explained
below. FIG. 10 shows a state where the filter F is inserted into
the opening 61 and FIG. 11 shows a state where the filter F is
detached from the opening 61.
[0060] As shown in FIGS. 12 and 13, the filter frame 65 according
to a first embodiment may have approximately a rectangular frame
shape. In the first embodiment, an L-shaped lock claw 65b may be
provided at an upper portion of the filter frame 65, and an
engagement portion in the form of a downwardly extending
rectangular plate 65a is provided at a lower portion of the filter
frame 65. The filter frame 65 may be retained within the opening 61
by an elastic force (bracing force) in the up-to-down direction
utilizing elastic deformation of the lock claw 65b, by which a
length between the upper lock claw 65b and the lower engagement
portion 65a can be changed. As shown in FIG. 9, a claw engagement
portion 61b may be provided at the upper portion of the opening 61,
and an engagement recess 61a at the lower portion of the opening
61. The filter frame 65 may be held in an engagement state with the
opening 61 by inserting the lower engagement portion 65a into the
engagement recess 61a and then inserting the upper lock claw 65b
into the claw engagement portion 61b via elastic deformation of the
upper lock claw 65b.
[0061] The filter F may be attached to the opening 61 over the
ventilation ribs 62 in an extended state (in a state where the
opening 61 is closed) by the filter frame 65 being retained. The
filter frame 65 in the first embodiment may be attached to the
opening 61 without rattling by elastically engaging the lock claw
65b with the claw engagement portion 61b by use of the elastic
deformation of the lock claw 65b in the up-to-down curving
direction. In order to detach the filter frame 65 from the opening
61, the upper lock claw 65b may be detached from the claw
engagement portion 61b by the elastic deformation of the lock claw
65b in the up-to-down direction, and then the lower engagement
portion 65a may be detached from the engagement recess 61a.
Maintenance work on the filter F can be performed by detaching the
filter frame 65.
[0062] FIG. 14 shows a state where the filter F is attached to the
intake window 60 by use of a filter frame 66 of a second embodiment
that has a different attaching structure from that of the filter
frame 65. Similarly to the filter frame 65, the filter frame 66 may
be integrally formed around the filter F. FIG. 15 shows a state
where the filter F is attached to the opening 61, and FIG. 16 shows
a state where the filter F is detached from the opening 61. As
shown in FIGS. 17 and 18, the filter frame 66 of the second
embodiment may have an approximately rectangular frame shape. An
L-shaped engagement portion 66c may be provided at the upper
portion of the filter frame 66 of the second embodiment, and an
operation plate 66a extending downwards may be provided at the
lower portion of the filter frame 66. The lock claw 65b of the
first embodiment and the engagement portion 66c of the second
embodiment may be formed approximately in the same L-shaped manner.
However, the lower operation plate 66a may be provided at the
lowest portion of the filter frame 66 via a U-shaped elastic
portion 66b, which is located immediately above, and to the right
of, the lower operation plate 66a, and is connected to the exterior
periphery of the filter frame 66. In the second embodiment, a pair
of front and rear engagement claws 66d may be provided on the front
and rear ends of the lower surface of the elastic portion 66b. A
pair of front and rear claw receiving portions 61d, that are
complementary in shape and fitting to the engagement claws 66d may
be provided at the front and rear ends of the lower portion of the
opening 61.
[0063] In contrast to the filter frame 65 of the first embodiment,
by first inserting the upper engagement portion 66c into the upper
claw engagement portion 61b and then second by fitting the lower
operation plate 66a into a shallow housing recess 61c that is
provided at the lower portion of the opening 61, the pair of the
engagement claws 66d provided at the lower portion of the elastic
portion 66b may elastically engage with the claw receiving portions
61d on the side of the opening 61. In this way, the filter frame 66
may be in a held state where it is complementarily engaged with the
opening 61.
[0064] The filter F may be attached to the opening 61 over and
outward of the ventilation ribs 62 in an extended state (in a state
where the opening 61 is closed) via the filter frame 66 of the
second embodiment being held by elastic engagement within the
opening 61. The filter frame 65 of the first embodiment may be
retained in the opening 61 by use of the elastic deformation of the
lock claw 65b in the up-to-down curving direction. Contrary to the
filter frame 65 of the first embodiment, the filter frame 66 of the
second embodiment may be held in the opening 61 by elastic
engagement of the engagement claw 66d with the claw receiving
portion 61d which is caused by the elastic force of the provided
U-shaped elastic portion 66b. In order to detach the filter frame
66 from the opening 61, the engagement state of the engagement claw
66d with the claw receiving portion 61d may be released by the
lower operation plate 66a being pushed upwards against the U-shaped
elastic portion 66b, and then by moving the lower operation plate
66a leftwards (outward and towards the user relative to the opening
61 of the grille 60 on the left side of the device 1) and
downwards, the engagement portion 66c can be pulled out from the
claw engagement portion 61b. In this way, the filter frame 66 can
be detached from the opening 61. Similar to the filter frame 65 of
the first embodiment, maintenance work on the filter F can be
performed by detaching the filter frame 66 from the opening 61.
[0065] According to the electric power tool 1 of the present
embodiment discussed above, in a so-called angle polisher, the
battery pack 50 may be attached to the upper surface side of the
battery attachment portion 40 that is provided at the rear portion
of the grip 30. As discussed above, in the angle polisher, the
output axis P may be disposed in the up-to-down direction at the
front portion of the tool main body 10 that houses the electric
motor 11 such that the axis P intersects and is orthogonal to the
motor axis J of the electric motor 11, and the output shaft 24 to
which the tip end tool 2 is attached may be provided at the lower
portion of the output portion 20, which is at the front portion of
tool main body 10. Because of this configuration, in a working
posture held by the user where the tip end tool 2 is directed
toward the working surface W, the battery pack 50 does not directly
come into contact the working surface W, thereby preventing
occurrence of troubles such as, for example, the formation of
unintended flaws or scratches on the working surface W.
[0066] Furthermore, the battery pack 50 may be attached to the
battery attachment portion 40 such that its thickness direction
(the shortest dimension of the parallelepiped shape) is aligned
with the up-to-down vertical direction, and such that the
connection portion 51 of the battery pack 50 faces downward with
respect to the upper peripheral surface of the battery attachment
portion 40. Because of this configuration, the battery pack 50 may
be attached to the battery attachment portion 40 such that the
upward protruding length of the battery pack 50 is configured to be
the shortest. Because the upward protruding length of the battery
pack 50 is minimized in this manner, when the user holds the grip
30 while stretching their hand above the battery pack 50, it is not
necessary for the user to worry about inadvertently contacting or
hitting the battery pack 50 with their hand. Thus, this enables the
user to easily perform a wide range of polishing work by being able
to stretch their hand in the forward direction above the battery
pack 50. In this respect, maneuverability and ease of use of the
electric power tool 1 is improved.
[0067] Furthermore, according to the exemplified electric power
tool 1, the entire outer peripheral circumference of the ovular
lower surface of the battery attachment portion 40 (the side of the
working surface W) may be covered with the elastic resin layers 45
made of elastomer rubber. Because of the presence of the elastic
resin layer 45, any adverse impact may be reduced and/or avoided
when the battery attachment portion 40 contacts the working surface
W, and also due to the surface characteristics of the elastomer
rubber, the formation of flaws or scratches on the working surface
W may be prevented.
[0068] Furthermore, as described above the lower peripheral surface
of the tool main body 10 may also be covered with the elastic resin
layers 18 made of elastomer resin as the elastic member, thereby
furthermore preventing formation of flaws or scratches on the
working surface W upon contact with said working surface W.
[0069] It is noted that the present teachings are not limited to
the above-described embodiments, and it is understood that
variations and modifications may be effected without departing from
the spirit and scope of the present teachings. In the present
embodiment, the battery pack 50 may be attached to the battery
attachment portion 40 such that its thickness direction (the
shortest dimension of the parallelepiped shape) is aligned with the
up-to-down direction. However, the battery pack 40 may be attached
to the upper surface of the battery attachment portion 40 such that
its longitudinal direction is aligned with the up-to-down direction
instead (the battery pack 40 is in an erected state, with its
longest dimension aligned with the vertical up-to-down direction).
Even if the battery pack 40 is disposed in the erected state,
because the battery pack 40 is attached to the upper surface of the
battery attachment portion 40, direct contact of the battery pack
40 with the working surface W is prevented, thereby preventing the
formation of flaws or scratches on the working surface W.
[0070] Furthermore, in the present embodiment, the rechargeable
polisher may be exemplified as the angle electric power tool 1.
However, the exemplified arrangement configuration of the battery
pack can be applied to other angle electric power tools such as,
for example, an impact driver, a grinder, a so-called multi tool,
etc. Especially, it may be sometimes necessary for the user to
stretch the hand while using the tool, and thus with this paradigm
of engagement the other mentioned applied electric power tools may
also become useful for the user as well.
[0071] Furthermore, as an alternative to the angle polisher in
which the motor shaft is perpendicular to the output shaft as
discussed in the above embodiment, the rechargeable polisher may
also be of a so-called vertical type, in which the motor shaft is
parallel to the output shaft. In this type of polisher, the total
length of the tool body may become short in the front-to-rear
direction, thereby improving operability in certain spaces.
Regarding a movement of the output shaft, a so-called rotary
movement other than the orbital movement discussed above may be
applied to the tools.
[0072] Furthermore, in the present embodiment, the battery pack 50
may be attached/detached in the front-to-rear direction. However,
in an alternative embodiment, the battery pack 50 may be
attached/detached in the left-to-right direction. Furthermore, in
the present embodiment, one battery pack 50 may be attached to the
upper surface of the battery attachment portion 40. However, in an
alternative embodiment, the electric power tool may be configured
such that a plurality of battery packs are attached to the battery
attachment portion. In said case, where a plurality of battery
packs are attached to the battery attachment portion, it may be
desirable that the battery packs are attached/detached in the
left-to-rear direction.
[0073] Furthermore, in the present embodiment, the
slide-attachment-type battery pack 50 may have an approximately
rectangular box shape with six faces, and may have rail receiving
portions 52 for slidably guiding the rails and have terminal
receiving portions 53 and 54 on one face (the bottom basal surface
of connection portion 51). However, other attachment interfaces of
battery packs may be used. For example, a battery pack may be an
insertion attachment type battery pack, which may have a
rectangular box shape with six faces and also may have a bar-shaped
insertion portion on one face. Alternatively, a battery pack may be
an insertion attachment type battery pack, which may have a bar
shape such that the whole body thereof can be inserted into the
electric power tool.
[0074] Furthermore, in the present embodiment, the electric power
tool may be operated by DC power such as the battery pack. However,
as an alternative, the present embodiment can be applied to an
electric power tool that is operated by AC power, such as mains
power, which may be supplied through a power cord disposed at the
rear portion of the grip. Similarly to the electric power tool
operated by DC power, the elastic resin layers 21c, 21d, 21e, 18,
36a for preventing flaws and scratches may be provided on the
electric power tool operated by AC power.
* * * * *